named array proof of concept

named_array.py

import numpy as np
from typing import Sequence

class NamedArray(np.ndarray):
    def __new__(cls, array: np.ndarray, names: Sequence[str]):
        assert array.shape[-1] == len(names)
        obj = np.asarray(array).view(cls)
        obj.names = names
        obj._lookup = dict(zip(names, range(len(array))))
        return obj

    def __array_finalize__(self, obj):
        if obj is None:
            return
        self.names = getattr(obj, 'names', None)

    def __getitem__(self, item):
        if isinstance(item, str):
            item = self._lookup[item]
        if isinstance(item, slice):
            if isinstance(item.start, str):
                item = slice(self._lookup.get(item.start),
                             self._lookup.get(item.stop),
                             self._lookup.get(item.step))
        return super().__getitem__(item)